A large variety of consumer, and other, electronic devices are readily available throughout modern society to perform many varied functions. Many of such devices are practical necessities of modern life. Ready availability of, and operation of, such devices is expected by many.
Different ones of the electronic devices are formed of different types of circuitries, exhibiting differing load characteristics. And, concomitant with the differing load characteristics are differing power requirements. For instance, different circuitries require application of different voltage levels and different voltage polarities. The circuitries of the electronic devices typically are direct-current circuits, i.e., operate using direct current energy. However, due to the differing load characteristics of different ones of the electronic circuitries, different levels of operative power are needed by the different ones of the circuitries to power the circuitries.
In North America, and also many other portions of the world, power grids are in place that provide 110 volt, alternating current energy, the power derived from which is used to power electronic devices. When the electronic circuitries of the electronic devices are operative at power levels that differ with the power levels of the power provided by the power grid, power converters are needed to convert the grid-supplied power into energy of characteristics needed to operate the electronic device.
A power converter operates to convert the energy characteristics of the grid-supplied power into characteristics appropriate to power the electronic device. As many typical electronic devices are formed of circuitries that utilize direct current energy, alternating current to direct current conversion is performed and voltage step-down, typically, of the voltage levels of the power is performed by a power converter that performs the power conversion.
When the energy supplied to the power converter is of characteristics, such as power supplied by an automotive battery power supply, the power converter operates in analogous manner to convert the supplied power into energy of characteristics appropriate to power the electronic device.
While power converters are sometimes of set characteristics, i.e., constructed to be operated in conjunction with only one, or one type of, electronic device, power converters that exhibit selectable devices are also available. Selectable power converters, that is, power converters that are capable of converting input energy of first characteristics into output energy of second characteristics are able to be used to power different electronic devices.
The selectable power converters are capable of exhibiting output energy characteristics of two or more characteristic values. And, some power converters are capable, at least in a step-wise manner, to generate output energy characteristics of numbers corresponding to the available steps.
U.S. Pat. No. 5,886,422 discloses, for example, a selectable output power converter. The output power converter disclosed therein utilizes a key that is used to determine the output characteristics of the output energy formed by the converter. The key includes a resistor, and the value of the resistor is determinative of the output energy characteristics of the converter. A key is inserted into a key way. And, once properly inserted, the value of the resistor forms a portion of the circuit of the power converter, and the value of the resistor is determinative of the energy characteristics exhibited by the power converter. The adaptability of the converter, however, is limited. The use of a passive device that must be physically connected to form a portion of the electrical circuit of the power converter generally requires that a separate key, and associated resistor, be available to form a portion of the circuit of the power converter to define the electrical characteristics of the output energy formed by the power converter. That is to say, the number of values that can be exhibited by the output energy formed by the power converter corresponds to the number of keys, and associated resistors, that are available by which to form portions of the electrical circuit thereof. The adaptability of the converter is, therefore, limited to the availability of keys to form portions of the power converter. In the event that a key is lost or misplaced, the power converter loses its capability of generating energy of energy characteristics corresponding to the lost or misplaced key.
And, other constructions of conventional power converters generally also exhibit limited adaptability for the same, or other, reasons. An improved power converter is, therefore, needed. The improved power converter would provide selectability that does not rely merely upon connection of a resistive element, or other passive component, into the circuit of the power converter, thereby to provide a power controller of improved operating adaptability.